The Tri-County Access Study area covers an approximately 1,000 square miles in northeastern Illinois and a portion of southern Wisconsin in order to fully understand the transportation problems and potential effects of any alternatives considered. The Study area includes three primary counties – Lake County in its entirety, eastern McHenry County and northern Cook County – and also considers the travel interrelationship with portions of DuPage and Kenosha counties.
The expansive Study area is consistent with the TCA Study Team’s commitment to taking a comprehensive, regional approach to examining transportation challenges and hearing from all who are affected. The boundaries were created with the understanding that our transportation challenges impact the entire region and are not defined by state borders.
The Study area conditions inform the development and evaluation of effects of the alternatives. However, proposed improvements to address the transportation needs will be developed and examined within a smaller subsection of the Study area – or the “Study Improvement Area” – where a need for transportation improvements is identified.